You may have noticed that the sidewalk buffer out (P4) feature line does not get drawn on your corridors. This holds for both the BasicSidewalk and UrbanSidewalk subassemblies.
The fix is easy- just add a marked point to the sidewalk buffer out.Â
Rebuild your corridor. It should work immediately upon rebuild.
Thanks to Fred in my training class today for pointing out that the points were not connecting! (And Nicky Z for confirming it was NOT just my imagination.)